Support for legacy PC5401 and some configuration options

[bmsec]

• PC5401 is the predecessor of IT-100 but it lacks some features.. The part of the protocol that is supported by PC5401 is nearly identical. So I think this would be also helpful for PC5401 owners.
• The send PIN command works a bit differently on IT-100 and PC5401.
• Some people might want to use the Stay arm feature. So hard coding a remapping for zero entry delay is a bit nasty. I placed a configuration option for this. -Arming more the one partitions should also work now, but it is not a perfect solution.

[SolidElectronics]

Thanks for this. I only use zero-entry, but separating it out into a configurable option is a good improvement.